This invention relates to production of hydrogen from different hydrocarbon fuels such as natural gas, gasoline, diesel, and alcohols such as methanol and ethanol.
Currently, the most cost effective method of producing hydrogen is centralized steam reforming of fuels such as natural gas. Rising energy prices and concern for the environment are prompting increased attention to hydrogen as an energy source. Hydrogen has been proposed as a clean fuel for the future with many applications including vehicles and stationary power (electric utility).
The largest volumes of merchant hydrogen are consumed in ammonia plants, in refineries and in methanol production. Only a fraction of hydrogen is currently used for energy purposes. However, hydrogen's share in the energy market is increasing with the implementation of fuel cells and the growing demand for low emission or zero-emission fuels.
Steam methane reforming (SMR), autothermal reforming (ATR) and catalytic partial oxidation (CPO) have been studied for distributed hydrogen production from natural gas (NG) for fuel cells applications. SMR utilizes reforming catalysts such as Ni to convert NG and steam to a synthesis gas (syngas). Conventional ATR typically includes a catalyst to facilitate both SMR and CPO reactions. These catalysts are typically not optimized for both the different type of reactions and therefore do not reach the maximum efficiency. Conventional SMR systems are not compact since large heat exchange surface areas are required to provide heat to the endothermic steam methane reforming reaction.
CPO (without an SMR catalyst) is a compact system. However, CPO generates a syngas with relatively low hydrogen (H2) to carbon monoxide (CO) ratio (˜2) and hence is better suited for Fischer-Tropsch or methanol synthesis than pure H2 production.
Therefore there is a need for a compact system for hydrogen production that is cost effective with efficient heat integration.